<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>

        {
            var a = 1
            let b = 1
        }
        console.log(a)
        console.log(b)

        var n = 1
        var n = 2
        console.log(b)

        let m = 1
        let m = 2
        console.log(m)

        const c = 1
        c = 2
        console.log(c)

    </script>
</body>
</html>